Train-dispatching system for railroads



March 3, 1931 5 w|GHT 1,794,566

TRAIN DISPA TCHING SYSTEM FOR RAILROADS Filed Sept. 21. 192'.

Patented Mar. 3, 1931 We j r i li;

SEDGWICK N. VfIGHT, OF ROCHESTER, NEW-YORK, ASSIGNOB T0 GENERAL RAILWAY SIGNAL COMPANY, OF ROCHESTER, NEW YORK TRAIN-DISPATCHING- SYSTEM FOR RAILROADS Application filed. September 21', men Serial naeznose.

This invention relates in. a general way to railway signaling systems, and more especially to standard absolute-permissive-block signal systems and the tumble-down circuits as used in Conjunction with such systems.

To those skilled. in the art of railway'signaling, and particularly A. P. B. circuits for single track signaling, it is readily understood how a trainleaving a passing'sicling immediately sets all opposing signals to danger, thereby preventing any trains from advancing, ofi'the next passing siding in advance, and into the intervening single track section. This feature is disadvantageous, in that, a train switching at a siding may hold up traffic from the next siding unnecessarily,

thus cutting down-the eliiciency of theroad.

At the same time this tumble-down feature is one that cannot be wholly eliminated because of its value to the safety of the system.

With the foregoing and other important considerations in mind, it is proposed in 'alc-f, cordance with the present invention to provide the necessary protection for a train switching at a passing siding without unnecessarily delaying traliic moving toward such siding. Generally speaking, it is proposed to at times allow a train the use of a passing siding and one automatic block beyond in either direction, and at the same time permit a train to proceed from the next passing siding to approach within a safe distance of the train engaged in switching. his act of at times allowing the train to make switchingmoves beyond the limits of the usual passing siding without interfering with a train entering the opposite end of the single track section in which the first mentioned train is making such switching moves, is for convenience called intercepting the tumble-down circuit. This because the tumble-down circuit has actually been made shorter. Generally speaking this intercepting of the tumbledown circuit is preferably accomplished by having a member of such switching crew operate a suitable manual operable device located near the switch at which such switching the east end of siding SD with its attendant moves are made, which if operated intercepts the tumble-down circuits and holds the signals associated with that track switch and one .whereby the tumble-down circuit is intercepted when the dual control selector is p0- sitioned for switch stand operation, and the tumble-down circuit extends throughout the entire single track section when the dual control selector is positioned forswitc'h machine operation. I I

More specifically, the present invention contemplates the use of a selecting relay located adjacent the first pair of intermediate signals in the single track section which relay if inone position holds the intermediate signal for approaching trafiic at stop and arranges the tumble-down circuit so that a train in the. block between the siding 1 and such first pair of intermediate signals will not interrupt the tumble-down circuit and will therefore permit strain io enter from the opposite end of the, single track section, This relay is preferablyso connected that it cannot pick up unless trafiic conditions in the single track section: are clear, or there is at least no departing train moving the first-block of the single tracksection, and which relay if once picked up will remain stuck up until the dual, control selector is moved to its normal switch machine position.

Other objects, purposes and characteristic features of the invention will appear as the description thereof progresses.

I In. describing the invention in detail reference will be made to the accompanying drawing, which is a'diagrammatic view of a standard A. P. B. system modified in acc'ords ance with this invention. p

Referring to the drawing there 1s shown type, are conventionallyshown as of the semaphore type, andare designated, 1, 1 2, 2 3, i, 5, {5, 7,7, 8 Lane 8. The signals 1 and 1 govern west-bound tra'liic onto the main track opposite the siding SD and into the siding, respectively, and are conveniently termed entering signals. The signals 2 and 2 govern the east bound trafiic off the main track opposite'the sid'ng SD and out of the siding, into the single track stretch O. These signals are called, for convenience, the east bound 'starting'signals. The stretch of single track O is preferably provided with opposite intermediate signals, as shown, or withstaggered intermediate signals in accordance with A, P. B. standard practice. Four interinediat signals,3, l,5and6areshown. These intermediate signals ofthe permissive type, as shown conventi'onally with a pointed blade. Signals 7 and 7 are the west bound starting signals forsid'ing S13 and signals 8 and 8 entering signals. All entering and starting signals are of the stopand-stay type as in dictated by their square' ended blades.

Allof these signals, except the take-siding signals 1 and 38 are preferably threeposition's'ignals, and governed in accordance with the condition of their associated polar home relays H (as indicated by the polar contacts) having a prefix corresponding to the reference number of the signal, as described in my prior Patent No. 1,294,736, dated February 18, 1919. A particular starting signal can of course only clear in accord ance with the condition of its home relay when the track switch assumes the position corresponding to such signal. The takesiding signals are preferably controlled only in accordance with the position'of the track switch and the associated detector track relay.

in order to simplify the drawing, the only circuits and relays shown are those of standard A. P. B. system necessary to illustrate the present invention in one form, and with the invention applied for facilitating traffic during the switching of a train in the vicinity of track switch TS only.

'7 The track switch TS is shown convention ally operated through a duel switch control selector DS by either an electric switch machine SM controlled from an interlocking tower or in accordance with a train dispatching system, or by a hand-thrown switch stand of the usual construction.

To describe the present invention clearly it will be necessary to briefly consider the usual operation of an absolute-permissiveblock system of the type shown. Therefore, the description of such operation will not be complete in all its details.

To simplify the wiring diagram and the explanation, positive, negative and common wires from a suitable source of energy, as for example a storage battery, have been indicated by the symbols B, N and C respectively, and EN is to indicate positive or negative.

For the purpose of illustration it will be well to consider the passing of an east bound train the siding SDonto the single track section O. (I hen the train enters the track section b the track is deene-rgized which deenergize the relay 3H through a cireuitwhich is obvious from the drawin T his action continues down the line througdi a tumble-down circuit (well known to those skilled in thelart), and results in setting all opposing signals,-such as 8, 5 and 7, to the "op position, thereby preventing an opposr from entering the opposite end of single track section 0. This feature is e desirable for protecting a train moving from irable for a train that is only switchn the vicinity of the track switch TS of g SD. This undesirable feature can be eliminated in accordance with the present invention without interfering with safety in a manner as presentlydescribed.

. At the signal 3 is located an extra stick relay,XS, the purpose of which is to set the sial 3 1n the stop position and prevent a completetumble-down due to a train in track section Z) or 0. The control circuit for this relay, assumingthe dual control selector to "be in the position for switch stand operation, is readily traced as follows :-starting,at a suitable source of energy B, dual selector contacts 9 in the reverse or dotted position, wire 10, winding of the XS relay, wire 11, wire 12, and either ofthe following two branches (1) wire 13, and a front contact 14 of the relay 31-1 to common return wire C, or (2) wire 15, and a front contact 16 of the usual directional stick relay 4S to the common return wire C. Once relay XS is energized it is stuck up by the following circuit: source of energy, dual selector contact 9 in the reverse or dotted position, wire 10, winding of the relay XS, wire 11, wire 17 and a front stick' contact 18 of the relay XS to G. This stic: circuit can only be broken by returning the dual control selector handle to normal, as shown.

With the dual-selector in the normal position, the energizing circuit for the 3H relay is as follows:source of energy B, selector contacts 9, wire 19, front contact 20 of the SD toward siding SD but it is very ing privileges will ordinarily first call the dispatcher and upon obtaining permission will place the dual selector in the reverse position enabling the'switch to be hand operated by the switch stand SS. places the selector contact 9 in the dotted position, the result of which is to de-energize the relay 3H by reason of opening of the circuit therefor previously traced, and other wise obvious. At the same time the selector contact 9 Wlll complete the energizing circuit, 7

as traced above, for the relay XS, providing there is no eastbound train between signals 2 and 4 in the single track section 0 which has already de energized relay 3H. In this connection it should be understood that by reason of the delay in dropping of contacts or relay I 3H, the relay XS will be picked up before rela'v 3H actuall dro 3s. The ener ization of relay XS will result in setting signal 3 at danger or stop, andin preventing a further tunible-down, such as ordinarily occurs. Or-

dinarily when relay 3H becomes deenergized it will in turn de-energize the relay 5H through opening of contact's28 ofthe following circuit-:source of energy BN (meaning positive or negative depending on whether the si nal 3 is at proceed or danger), front contact 28, of the relay 3H, wire 29, wire 30,

wire.31,backcontact 32 of the relay lS, wire 33, front contact 34 of the track relay TD, wire 35', front contact 36 of the relay TE, wire 37, winding of the relay 5H to C. With the home'relay 5H assuming the retracted position, it will in turn deenergize relay'7H by opening contacts 38' of the following circuit :source of energy EN, front contact 38 of the relay 5H,.wire 39, wire 40, back contact-41 of the relay 6S, wire 42, front contact 43 of the track relay TF, wire a l, front contact 45 of the track relay TG, wire d6, front contact i7 of thedetector track relay DTH, wire 48, winding of the relay 'ZHto C. It is thus seen that with relay XS in its retracted condition the entrance of an eastbound train in section Z) causes all westbound signals 2, 3 and 6 to assume the stop position. On the other hand, when relay 3H is deenergized by reason of shifting selector contact 9 to the dotted position, and relay XS is energized in response to this shifting of contact 9 as heretofore described, this change in the con XS shifts the source of'energy for the circuit of relay 5H, from relay 31-1 to relay XS, which control for supplying a new circuit may betraced as follows :source of energy BN (plus or minus), front contact l9 of the g This movement dition of energization of relays 3H and relay XS, wire 50, wire 30 etc. as previously traced, through relay 5H to C.

The train in question is therefore allowed to switch as far as to. signal 3 without interrupting the. tumble-down circuits and unnecessarily delaying westbound traflic in the single track section 0*, at the same time providing adequate protection for trains in the rear by means of signals 2 and 2 controlled by relay 2H. The circuit for relay 2H may be traced as follows :-'source of energy BN, front contact 51 of the relay 4H, wire 52, xvii-e545 (or BN, front contact of the relay 4S, wire '66 connecting to wire 54) back contact 55 of the relay 3S, wire 56, back contact 57of the relay XS,wi're 58,'front contact 59 of the track'relay TC, wire 60, front contact 61. of the track relay TB,-wire 62, front contact 63 of the detector track relay DTA, wire 64, winding ofthe relay 2H to C. During switching maneuvers, this: circuit is broken at the back contact 57 of the relay XS, thereby keeping signals 2and2 in the danger position due to de-energization of relay 2H.

Onreturning the dual selector to normal the original tumble-down circuits are restored through selector contact 9. It is of course understood that although the invention has been shown applied to the switch only, it may also be applied to the switch TS and may be applied to each end of every singletracl section, if desired.

It is thus seen that in the modified A. P. B.

system illustrated,-one embodiment of the present invention, the tumble-down circuit for putting all of the westbound si nals in their stop position normally extends fronithe signal2to the signal 8, but if the dual control selector DS is in the abnormal switch stand position, this tumble-down circuit extends only from the signal a to the signal 8. The ability to intercept the tumble-down circuit, so to speak, by the means described, enables a switch engine to m'ake switching moves on such track sections as a and 5 without in any way interfering with the entering of a train at the opposite end of the single track section 0. If a train does enter the opposite or east end of the single track section O when the tumble-down circuit is intercepted, that is the relay XS is energized, this train will encounter the signal 5 at caution and will be brought to a stop at the signal 3 so that this train is safeguarded against encountering the switching engine at speed. When the dual control selector is returned to its normal switch machine position the stick relay XS is de-energized and the'circuit arrangement for the signals functions in exactly the same way as that of an A; P. B. system to which the inventionis not applied. At first hand it would appear that the re lay XS might, with safety, be controlled directly by the contact 9 of the duel control select-or. Although this could be done it is not 'neer L track section U a oyiously the and Westbound train could not pase n reouirec :olhty O'i A it? Di v.

c, tecaise re is inter this co -d k Hositnat 's incomplete nn iestion has passed 9 and opening 01 contact 26 of relay KS. In this connection, the relay 8H nay be made slow to drop, or the contact 1% may be a slow ogening contact or may be one of the slow acting repeater relays operated by the relay 3?, in order to all-cw relay XS suthcient time to ick up before contact 1 opens. Further, if the east bound degartinp' just mentioned has actually nosed by signal 4, but is still on the track circuit 0, the stick relay lS will have beei picked up for obvious reasons,

andif the dual control selector is at this time operated to the dotted position the relay XS is picked up even though relay 31-1 is now 1 'lhe-picking up of this relay tirely safe, besaid eas boinid train signal 7 es no 1" a West J. u on the tom ion a on is .led for truin directions and in Whic the --d so that the entrance ifsuch single track secopp Si? signals in their L d in which the first signal the rear of such tan is held at stop,

,I se nd ,ignal is held at caution and the nais permted to clear in accordsuch train, and of g uch opp .:ing

1 sic'nals assuming the stop position until the h the progress means LOT at times preventi 1 enteiing tr; in has entered lHJO the singlet traclr ection a predetermined distance.

- combination with a single track railway sig' system of the type in which track secti n is signaled for train movenent in both directions and in Wl ich the sigials are controlled so that the entrance of a rain in one end of such track section places all of the opposingsignals in their stop condition and in which the first signal in the rear of such train is held at stop, the second in the rear is held at caution and the third signal in the rear is permitted to clear in accordance with the pro of such train, and of means for Varying t e effective length of signal next in the rear, and other means for rendering a particular signal ineffective to eluding track relaysfor controlling said signal rela s, means for rendering each signal relay inei'l'ective to control he continuity of the signal relay for the next signalin the I rear, and other means for rendering a par ticular signal relay ineffective to control the continuity of the circuit for thesignal relay oi the signal in the rear thereof.

5. In arailway si naling system, in combination, stretch of single track; a signal guarding the entrance to said stretch ateach end; intermediate signals located atintervals along thestretch for governing trafiic in one direction; a polarized signal circuit for controlling each signal; control means associated with the signal circuit for eachintermediate signal for controlling the continuity of the signal circuit of the signal neXt in the rear; means for rendering said control means ineffective; and manually operable means for placing a particular intermediate signal in its stop condition and rendering such signal ineilective to control the continuity of the signal. circuit for the next signal in the rear.

6; In arailway signaling system, in combination; asingle track railway divided into track sections'bypassing sidings, a starting signal at each end of eachsection, intermediate signals along a track section for governing traiiic'in both directions, tumble-down circuits for each section for causing a signal to put the nentsignal in the rear to stop, supplemental means for controlling the signals for one direction of traffic in accordance With the condition of the next signal in ad vance of such signal and the condition of occupancy ofthe intervening track, and other 7 means for placing a signal in the stop position without-causing the next signal in the rear thereof to be put to stop. v

' 7. In a railway signaling system, in com bination; a single traclr railway divided into track sections by passing sidings, a starting signal at each end of each section, intermediate signals along a track section for govern ing trailicin both directions,tumble-down circuits "for each sectlonfor causing a signal.

. to put the next signal in the-rear to stop,

ance with the condition of the next signal in, advance of such signal and the condition of supplemental means for controlling the Signals ior'one direction of traiiic inaccord occupancy of the intervening track, and means for varying the length 01" traclrway through Which the tumble-down circuits are capable of causing one signal to put to stop the next signal/in the rear.

- 8. In combination, a stretch of railway track, signals located at intervals for governmg traiiic'through sa d stretch, a signal relay for each-signal, means for. controlling the continuity of the circuit for each signal relay by the signal relay for the next si nal in advance, track circuits for the stret including track relays for controlling said signal relays, means for rendering each signal-relay ineffective to control the continuity of the signal relay for the next signal in the rear, and mean. for varying the effective length of the stretch through which signals are controlled in the manner described.

9. The method of controlling the signals of single track railroads whereon signals are provided for governing trafiic moving in both directions, which consists in normally controlling the signals of a single track section relay by the signal relay for the next signal in adyance, track circuits for the stretch in eluding track relaysfor controlling said signal relays, means for rendering each signal relay ineffective to control the continuity of the signalrelay for the next signal in the rear,

and means for intercepting the tumble-down circuitarrangement. p e

11. In a railway signaling system,'in combination; a track sections by passing sidings, a starting signal at each end of each section, intermediate signals along a track section for govern- .ing traffic inlboth directions, tumble-down circuits for each section for causing a signal to put the next signal in the rear to stop, supplementalmeans for controllingthe signals for one direction oftrafiic in accordance with thecondition of the next signal in advance of such signal and the condition 'of occupancy of the intervening traclr, and-means for interceptingsaidtumble down circuits. p y e 12. The combination with a railway signaling system of the single track absolute-permissive-block type, in which the entrance of a train into one end of a single track section causes the signals governing the entrance of'trains into the other end or said section to assume the stop condition,and in which an intermediatesignal isemployed to govern themovementof trains by. an intermed ate point; and of; meansior permitting s'wi tching movesto be madein" said Si gle track,

single track railway divided into ing system of the single track absolute-permissive-block tvpe, in which the entrance of a train into one end of a single track section causes the signals governing the entrance of trains into the other end of said section to assume the stop condition, and in which an intermediate signal is employed to govern the movementof trains by an intermediate point; and of means for permitting switchtrol selector for placing said intermediate signal in the stop position thus preventing the entrance ofa train at one end of said zone, and placing the signals governing the entrance of trains into the other end of said Zone at stop when said dual control selector is moved to operatively connect said switch stand to said track switch, said switching moves being made by train order and without obedience to said signals.

V In a railway signaling system, in com bination; a single track railway divided into track sections by passing sidings, a starting signal at each end of each section, intermediate signals along a track section for governing traiiic in both directions, tumble-down circuits for each section for causing a signal to put the next signal in the rear'to stop, supplemental means for controlling the signals for one direction of tratiic in accordance with the condition of the next signal in advance of such signal and the condition of occupancy of the intervening track, a stick relay near one of said intermediate signals which it energized places said one intermediate signal in the stop position and renders inactive the 'tumbledown circuit "to put thegnext signal'in the rear of said one signal to stop, pick-up circuit for said stick relaygincluding a manually operable contactand a contact closed it traflic conditions in advance ot said one signal are favorable, and a stick circuit for said stick relay including said manually operable contact and a front stick contact of said stick relay.

15. In a railway signaling system in combination; a single track railway divided into track sections by passing sidings, a starting signal at each end 03": each section, intermediate signals along a track section for governing traificin both directions, tumble-down circuits for each section for causing a signal to put the next signal in the rear to stop, supplemental mea -s for controlling the signals for one direction of traiiic in accordance with the condition of the next signal in advance of such signal and the condition of occupancy of the intervening track, a stick relay near one of said intermediate signals which if energized places said one intermediate signal in the stop position and renders inactive the tumble-down circuit to put the next signal in the r ar of said one si nal to stop, a pickup circuit for said stick relay including a manually operable contact in series with two contacts in multiple one of which is closed J! Vance of said one signal and the other of which is closed when a train is passing said one signal in the opposite direction to that in which said one signal governs traffic, and stick circuit for said stick relay including said manually operable Contact and a front stick contact or" said stick relay.

' In testimony whereof I aifix my signature.

SEDGVVICK N. WIGHT.

iavorable traihc conditions exist in ad 

